Hydraulic jack



March 24, 1953 M. GEESINK HYDRAULIC JACK Filed Aug. 15, 1947 IM WY IN VEN TOR MYA/az/er 625mm ATTORNEX Patented Mar. 24, 1953 HYDRAULIC JACK Myndert Geesink, Weesp, Netherlands; Marretje Gijsbertha Geesink-de Graaf, Gijsbertus van den Burg, Catharina Jacoba van den Burg- Geesink, Aaltje Gerarda. Bokelmann-Geesink, Reinhard Frederik Hendrik Bokelmann, Ar-

nolda Catharina Magdalena Geesink, and

Myndert Marten Geesink, sole heirs of the estate of Myndert Geesink, deceased Application August 13, 1947, Serial No. 768,463 In the Netherlands August 15, 1946 9 Claims. (01. 121 40) This invention relates to jacks and more particularly to fluid Operated jacks. I

It is the principal object of the present invention to provide a fluid operated jack with mechanically operative locking means for locking the jack in selected operative position.

It is another object of the invention to provide afiuid operated jack with locking means which has simplicity of assembly, economy of construction and efficiency in operation.

The novel features that are considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation will best be understoodfrom the following description of specific embodiments when read in connection with the accompanying drawing, wherein like reference characters indicate like parts and in which:

Figure l is a cross-sectional view taken axially through a jack in accordance with the present invention, and

Figure 2 is a fragmentary cross-sectional view similar to Figure 1 but illustrating a modification.

Referring now to the drawing, specifically to Figure 1, a jack in accordance with the present invention comprises a cylinder 1 having a piston 1 2 slidable therein. A hollow rod 3is carried by said pistonand extends through one end closure of said cylinder I. An eye 4 or the like is fixed on the outer end of said piston rod 3 for engaging the part to be jacked up or moved and when so engaged the eye 4 retains the rod 3 and piston 2 against rotation.

a A screw spindle 5 is mounted in the opposite end of the cylinder l and passes through and .threadedly-engages an internally threaded bore centrally in the piston 2 and telescopesinthe hollow rod 3. The threaded engagement between the'spindle and the piston is non-selflocking so that relative axial movement between said piston and spindle is readily effective and will resultin relative rotational movement due to said threaded engagement.

The spindle 5 has a brake disc 6 mounted thereon below the piston 2 and retained in fixed relation thereto by a key or the like 6'. The lower end of the cylinder l is closed by a brake drum 1 which is cooperative with said disc 6 and 1. 1.. A thrust bearing 9 is mounted beneath the drum 1 for engagement by said collar 8' when the spindle is lifted and precludes excessive friction on the collar 8 that would inhibit rotation of the spindle.

, A fluid passage opening I6 is provided in the cylinder I immediately above the drum 1 and below the piston 2. The brake disc 6 is provided with a port I l for passage of fluid to both sides thereof and thereby to equalize the pressure thereon and prevent development of vacuum that would hold said disc 6 in braking engagement with said drum 1. The lower end of the spindle 5 extends into a supplementary cylinder [2 on the lower end of the cylinder I and a plunger 13 slidable in said supplementary cylinder is connected with said spindle.

In operation, the jack is positioned with the eye 4 engaging the part to be lifted or moved and fluid under pressure is then admitted through the opening I0 into the cylinder l. The pressure of the fluid causes axial displacement of the piston 2 with its rod 3 and eye 4. This displacement initially causes the limited axial movement of the spindle 5 that is permitted by the collar 6 to disengage the brake disc 6 from the brake drum 1 and subsequent piston displacement merely causes rotation of the spindle 5 due to the threaded engagement therebetween.

When the piston has been displaced sufficiently to lift or move the part the desired distance, the admission of fluid to the cylinder l is stopped. The pressure or load of the part on the eye 4 will cause the piston to move in the opposite'direction and this movement will be transmitted to the spindle 5 to the extent permitted byengagement between the brake disc 6 and drum 1 which will prevent both axial and movement of the spindle 5.

As the spindle is then held against rotation by the brake, the piston 2 will be locked by the threaded engagement with the spindle against further axial displacement as long as the pressure of the part is maintained against the eye 4 so rotational as to preclude rotation of the piston and conse- Obviously, a mechanically operated release may besubstitutedfor the fluid operated release of the supplementary cylinder l2: and-plunger I3. A suitable mechanical release is shown, by way of example, in Fig. 2. In this case, the lower end of the spindle 5 extends beyond the lower end closure of the cylinder l and the end; of said spindle is engageable by an eccentric or cam 14 that is operable by a crankor-lever l5; In other .mitting fluid under pressure tosaid cylinder so as to impart movement to said piston; said piston having an axial opening; a-non-selflocking screw thread provided about said opening; a nonselflocking screw spindle extending through said opening andtbeing engaged'by said screw thread, the said spindle being capable of limited axial Vmovement relative to said cylinder under the;

weight off the load; locking'means cooperative between; said spindle and saidvcylinder for looking; saidi spindle against rotation, the said locking means being operated upon axial movement of. said-spindle; and means for, moving saidspin-- dle to release-saidllocking means.

' 2; In a. hydraulic jack; for, non-rotatable loads, incombination, acylinder; a piston fitting therein: and axially movable therein; means for supporting the load: on said piston; means for. a'dmitting fluid underapressure to. said cylinder so as to impart movement to said piston; said piston having an axial opening; a non-selflocking screwthread provided aboutsaid opening; a nonselfiock-ing screw spindleaextending through said opening and being engaged by said'screW-thread,

:the saidspindle being capable of limited axial movement relative to said cylinder under the 1 weight of the load; locking'meanscooperative between said spindle and said cylinderfor lookingsaid spindle against rotation, ,the: said lock- .ingmeansbeingoperated upon axial movement of'said spindle; and means operated by. fluid underpressure for moving saidspindle to; release lockinggmeans.

3-."In a hydraulic jack for non-rotatable; loads, incombin ation, a cylinder; apiston flttingztherein and axially movable therein; means for supporting the'load on said" piston; means for admitting-fluid under pressure to said cylinder so as to impartmovement to said piston; said piston lraving antaxi'al opening; a non-selfiocking screw thread provided about said opening; a nonselflocking screw spindle extending through said opening and being'engagedby said screw thread,

v the said spindlevbeing capable of limited axial .movement relative to said cylinder under the weight of the load; locking means cooperative betweensaidspindle and said cylinder for. lockingsaid; spindle against rotation. the said, locking mean'sibeing operated upon axial movement '-of said spindle in one direction; a movable abutment; and means for; engaging said spindle by said abutment so as toimpart-axial movementtto The invention, therefore, is not. to be said spindle in the opposite axial direction so as to release said locking means.

4:. In a.hyd-raulic jack for nonsrotatable loads, in combination, a cylinder; a piston fitting therein and axially movable therein; means for supporting the load on said piston; means for admitting fluid under pressure to said cylinder so as to impart movement to said piston; said piston having an axiallopening; a non-selfiocking screw threadproyided about said opening; a non-selflocking screw. spindle extending through said opening and being; engaged by said screw thread, the said spindle being capable of limited axial movement relative to said cylinder under the weight of the load; cooperating wedge elements associated with, said spindle and said cylinder mfor; locking said spindle against rotation when forced together by axial movement of said spindle inone axial direction; and means for forcing said spindle in the opposite axial direction so asto disengage said wedge elements.

5. In a hydraulic-jackifornon rotatable loads, in combination, a; cylinder; a piston fitting therein and axially movable therein; means for; supporting the load on said piston; means for admitting fluid under pressure to said cylinderso asto impart movement to said piston; said piston having an axial opening; a non-selflocking screw thread provided about said opening; a non-selflocking screw spindle extending through said opening andbeing engagedbysaid screw thread, the said spindle being capable of limitedaxial movement relative to said: cylinder under the weight of the load; cooperating wedge elements associated with said spindle and said cylinder for locking said spindle against rotation when forced together-by axial movement of said spindle in one axial direction; and means operated by fluid under pressure for forcing said spindle in the opposite axial direction so as to disengage said wedge elements.

6. In a hydraulic jack for non-rotatable-loads, in combination, a cylinder; a piston-fitting therein and axially movable therein; means'for supporting the load on said piston; means for admitting fluid under pressure to said cylinder so as to impart movement to said piston; said piston having an axial opening; a non-selflocking screw thread provided about said opening; a non-selflocking screw spindle extending through said opening and being engagedby' said screw thread, the said spindle being capable of limited axial movement relative to said cylinder under the weight of the load; cooperatingwedgeelements associatedwith said spindle and said-cylinder for locking said spindle, against rotation" when forced together by axial movement-oflsaid' spindle in one axial direction; a movable abutment;

and means for engaging said spindle by said abutment so as to impart axial movement in the opposite direction thereto thereby releasing said wedge elements.

'7. In a, hydraulic jack for non-rotatable loads, in combination, a cylinder; a piston fitting therein and axially movable therein; means for supporting the load on said piston; means for admitting fluid under pressure tosaid cylinder so as to impart movement to said piston; said piston having anaxial opening; a non-selflocking screw thread provided about said opening; a non-selflocking screw spindle extending through said opening-and being engaged by. said screw thread, th said spindle being capable of. limited axial movement relative to said: cylinderiunder the weight of the load; locking imeanss cooperative between said spindle and said cylinder for locking said spindle against rotation, the said locking means being operated upon axial movement of said spindle with said movement under the influence of the load operating to lock said means and said movement induced by piston movement due to the fluid pressure in the cylinder operating to release said means and separate means for moving said spindle to release said locking means. 8. In a locking device for fluid-actuated jacks for non-rotatable loads, a cylinder, a piston fitting in and axially movable in the cylinder, a hollow piston rod fixedly connected to the piston and; supporting the load to hold said piston against turning, said piston having an axial internally threaded opening, a non-selflocking screw spindle loosely threaded through the axial threaded opening in the piston, held against free unlimited axial movement in the cylinder and extending loosely into the hollow piston, means to admit fluid pressure to the cylinder beneath the piston to raise the latter and load supported by the piston rod, the said spindle being capable of limited axial movement relative to said cylinder under the weight of the load, a locking portion in said cylinder locking means splined on the spindle and engageable with said locking portion for locking said spindle against rotation, said locking means being operated upon axial movement of said spindles, and means for moving said spindle to release said locking means.

9. In a hydraulic jack for non-rotatable loads, a cylinder, a piston fitting in and axially movable in the cylinder, a tubular piston rod rigidly connected to the piston and extending from the cylinder for connection to and supporting the load to hold said piston against rotation, means for admitting fluid under pressure to said cylinder so as to impart axial movement to said piston, said piston having an axial internally threaded opening a non-selflocking coarse thread screw spindle loosely rotatably engaged through the axial threaded opening in the piston and movably extending loosely into the tubular piston rod, means between the spindle and cylinder beneath the piston to hold the spindle against unlimited axial movement but allowing limited downward axial movement of said spindle under the weight of the load, a locking ring held in the cylinder around the spindle beneath the piston, a friction braking member on the lower portion of the spindle and operatively engageable with the ring upon downward movement of the spindle to hold the spindle against rotation, an extension on the spindle extending through and below the lower end of the cylinder, and means acting on the lower end of the extension to lift the braking member away from the ring to release same to permit rotation of the spindle and raising of the piston under the influence of the fluid under pressure or lowering thereof when the pressure is released.

MYNDERT GEESINK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 679,421 Halsey July 30, 1901 1,101,976 Vaughan June 30, 1914 1,121,414 Stafiord Dec. 15, 1914 2,274,334 Keller Feb. 24, 1942 FOREIGN PATENTS Number Country Date 436,271 France Jan. 19, 1912 

